This short scene allows the audience once more into the private thoughts of the murderous couple, while holding the action momentarily in suspense. As the hired killers make their way toward Banquo, Macbeth and his wife meet secretly. His wife attempts to soothe his troubled mind but ironically feels the same doubts herself. Killing the king has provided them with many more difficulties than they first envisioned. To the astonishment of his wife, Macbeth reveals his plan to murder Banquo.
Dramatically and poetically, this scene precisely mirrors Act I, Scene 5. Then, Duncan's death was being plotted; now, the death is Banquo's (although Lady Macbeth is initially unaware of this). In the earlier murder, Lady Macbeth was most in command; in this murder, Macbeth is. Where formerly Macbeth was the one who needed convincing, now the weaker role passes to his wife. Macbeth's line "make our faces vizards (visors) to our hearts" recalls Lady Macbeth's earlier words "[t]o beguile the time, look like the time." Similarly, Macbeth's injunction to the spirits of darkness "Come, seeling night . . . " is an echo of the speech of Lady Macbeth's beginning "Come, thick night . . . ."
Despite Macbeth's personal bravado, neither he nor his wife seems entirely at ease. Lady Macbeth talks of her "doubtful joy" and Macbeth of his "restless ecstasy." In the world that the Macbeths have created for themselves, total peace no longer exists, and what has been achieved is only a half-measure. Even the dead King Duncan is able to achieve more totally what Macbeth never can: a respite from "life's fitful fever."
While Lady Macbeth appears to be looking back at the previous murder, Macbeth looks forward, anticipating the next murder, of which Lady Macbeth is not yet fully aware. That distinction between their two states of knowledge allows Shakespeare to play once more on the power relationship between husband and wife. Here, then is yet another reversal of character, and it is shown in two major ways: first, by Lady Macbeth's innocent-sounding questions and, second, by Macbeth's adoption of animal imagery. In Act I, Scene 5, Lady Macbeth was the one who spoke of "the raven" and "the serpent." Now Macbeth takes on the same language of horror, imagining his mind to be "full of scorpions," and speaking of the "bat" and the "shard-born (dung-bred) beetle."
The most powerful moments of the scene are the final ones in which Macbeth calls for the cancellation of the bond between himself and the world. "Bond" is more than simply a simile from the world of legal jargon. Just as Lady Macbeth earlier wanted to lose her sex, Macbeth now desires to be rid of his humanity. His direct connection with the natural world into which he was born threatens to keep him "pale" or fearful. A final point to make about these lines is the way in which the rhythmical stress falls unusually on the first syllable of the word "cancel":
"And, with thy bloody and invisible hand
Cancel and tear to pieces that great bond . . . ." (49-50)
Metrically, as well as dramatically, Macbeth is moving inexorably toward his tragic destiny. Meanwhile his wife, once so calm and collected, is losing that composure. Macbeth's line "Thou marvell'st at my words" suggests, like a stage direction, some moving response in her.
scotch'd (13) injured
both the worlds (16) earth and heaven
foreign levy (25) foreign invasion
lave our honours . . . streams (33) show ourselves to be honourable by washing ourselves in acts of flattery
vizards (34) masks